A dual-mode microstrip sensor for simultaneously extracting complex permittivity and permeability of magnetodielectric samples

Abstract

This paper proposes a dual-mode microstrip sensor for simultaneously retrieving the electromagnetic parameters of magnetodielectric (MD) materials. The microwave microstrip sensor consists of a 50Ω standard microstrip line and a modified magnetic-LC resonator. In the MLC structure, the center arm is replaced with a meander slot to improve the electric filed confinement, with interdigital capacitor structures inserted into the opening of the split ring to enhance magnetic field density. The complex permittivity ( ε r ) and permeability ( μ r ) of the MD samples are simultaneously retrieved by measuring S-parameters of odd- and even-modes. The frequency compensation and artificial neural network are employed to improve the retrieval accuracy. The proposed sensor is fabricated and tested, and the sensitivities for retrieving permeability and permittivity reach 10.78% and 4.71%, respectively. • A dual-mode microstrip sensor is proposed to fully characterize magneto-dielectric materials, with the measurement steps reduced to be one step in comparison with previously proposed sensors. • The meander slot and interdigital capacitors are adopted to improve field confinement, and the frequency compensation and artificial neural network model are introduced to improve the retrieval accuracy. • The even-mode and odd-mode are employed to retrieve complex permeability and permittivity, respectively, and the proposed sensor exhibits enhanced capability than previous designs.